Investments (Narrative) (Details) (USD $)	12 Months Ended									12 Months Ended			3 Months Ended			3 Months Ended				3 Months Ended
	Dec. 31, 2011		Jan. 02, 2011		Jan. 03, 2010	Dec. 31, 2011 Berkshire Hathaway Inc [Member]	Jan. 02, 2011 Berkshire Hathaway Inc [Member]	Dec. 31, 2011 Berkshire Hathaway Inc [Member] Class A Common Stock [Member]	Jan. 02, 2011 Berkshire Hathaway Inc [Member] Class A Common Stock [Member]	Jan. 03, 2010 Berkshire Hathaway Inc [Member] Class B Common Stock [Member]	Dec. 31, 2011 Berkshire Hathaway Inc [Member] Class B Common Stock [Member]	Jan. 02, 2011 Berkshire Hathaway Inc [Member] Class B Common Stock [Member]	Oct. 02, 2011 Corinthian Colleges, Inc. [Member]	Apr. 03, 2011 Corinthian Colleges, Inc. [Member]	Dec. 31, 2011 Corinthian Colleges, Inc. [Member]	Oct. 02, 2011 Bowater Mersey Paper Company [Member]	Sep. 27, 2009 Bowater Mersey Paper Company [Member]	Dec. 31, 2011 Bowater Mersey Paper Company [Member]	Dec. 31, 2011 Classified Ventures LLC [Member]	Sep. 27, 2009 Other immaterial affiliate [Member]
Schedule of Equity Method Investments [Line Items]
Shares held in investee company								2,214	2,214		424,250	424,250
Company's investments in marketable equity securities	$ 303,201,000	[1]	$ 340,910,000	[1]	$ 353,884,000	$ 286,400,000	$ 300,700,000								$ 16,800,000
Percentage of total fair value of the Company's investments						94.00%	88.00%
Equity Method Investment, Ownership Percentage																		49.00%	16.50%
Percentage Of Common Stock Held By Investee Company						23.00%
Percentage Of Investment Held In Investee Company						less than 1%
Available-for-sale Securities, Gross Unrealized Gains						129,100,000	143,400,000
Impairment write-down on a marketable equity security	53,793,000		0		0								23,100,000	30,700,000
Impairment charge on the Company's investment in affiliate	9,200,000				27,400,000											9,200,000	27,400,000			1,600,000
Payments to Acquire Marketable Securities										$ 10,800,000

[1] The Company’s investments in marketable equity securities are classified as available-for-sale.